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Dataset

 

MOD04_L2 - MODIS/Terra Aerosol 5-Min L2 Swath 10km

Update Frequency: As Needed
Latest Data Update: 2023-06-19
Status: Ongoing
Online Status: ONLINE
Publication State: Published
Publication Date: 2021-04-15
Download Stats: last 12 months
Dataset Size: 1.41M Files | 3TB
Abstract

These data are a copy of MODIS data from the NASA Level-1 and Atmosphere Archive & Distribution System (LAADS) Distributed Active Archive Center (DAAC). The copy is potentially only a subset. Below is the description from https://ladsweb.modaps.eosdis.nasa.gov/missions-and-measurements/products/MOD04_L2

"The MODIS Aerosol Product monitors the ambient aerosol optical thickness over the oceans globally and over a portion of the continents. Further, the aerosol size distribution is derived over the oceans, and the aerosol type is derived over the continents. Daily Level-2 data are produced at the spatial resolution of a 10x10 1-km pixel array (at nadir).

Prior to MODIS, satellite measurements were limited to reflectance measurements in one (GOES, METEOSAT) or two (AVHRR) channels. There was no real attempt to retrieve aerosol content over land on a global scale. Algorithms had been developed for use only over dark vegetation. The blue channel on MODIS, not present on AVHRR, offers the possibility to extend the derivation of optical thickness over land to additional surfaces. The algorithms use MODIS bands 1 through 7 and 20 and require prior cloud screening using MODIS data. Over the land, the dynamic aerosol models are derived from ground-based sky measurements and used in the net retrieval process.

Over the ocean, three parameters that describe the aerosol loading and size distribution are retrieved. Pre-assumptions on the general structure of the size distribution are required in the inversion of MODIS data, and the volume-size distribution is described with two log-normal modes: a single mode to describe the accumulation mode particles (radius < 0.5 µm) and a single coarse mode to describe dust and/or salt particles (radius > 1.0 µm).

The quality assurance control of these products will be based on comparison with ground stations and climatology.

For additional details see the MODIS Atmospheres web site page onCollection 6.1 Updates. "

Shortname: MOD04_L2 , Platform: Terra , Instrument: MODIS , Processing Level: Level-2 , Spatial Resolution: 10 km , Temporal Resolution: 5 minute , ArchiveSets: 61 , Collection: MODIS Collection 6.1 - Level 1, Atmosphere, Land (ArchiveSet 61) , PGE Number: PGE04 , File Naming Convention: MOD04_L2.AYYYYDDD.HHMM.CCC.YYYYDDDHHMMSS.hdf YYYYDDD = Year and Day of Year of acquisition HHMM = Hour and Minute of acquisition CCC = Collection number YYYYDDDHHMMSS = Production Date and Time AYYYYDDD = Year and Day of Year of acquisition , Citation: Levy, R., Hsu, C., et al., 2015. MODIS Atmosphere L2 Aerosol Product. NASA MODIS Adaptive Processing System, Goddard Space Flight Center, USA: http://dx.doi.org/10.5067/MODIS/MOD04_L2.061 , Keywords: Climate Change, Atmospheric Correction, Aerosol Optical Depth/Thickness

Citable as:  National Aeronautics and Space Administration (2021): MOD04_L2 - MODIS/Terra Aerosol 5-Min L2 Swath 10km. National Aeronautics and Space Administration, date of citation. https://catalogue.ceda.ac.uk/uuid/f5e2886edf254a42804b9a77af6d5c9c/
Abbreviation: MOD04_L2
Keywords: Climate Change, Atmospheric Correction, Aerosol Optical Depth/Thickness

Details

Previous Info:
No news update for this record
Previously used record identifiers:
No related previous identifiers.
Access rules:
Public data: access to these data is available to both registered and non-registered users.
Use of these data is covered by the following licence(s):
https://modaps.modaps.eosdis.nasa.gov/services/faq/LAADS_Data-Use_Citation_Policies.pdf
When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record.
Data lineage:

Data were downloaded from https://ladsweb.modaps.eosdis.nasa.gov/archive/allData/ to support UK research groups, especially NCEO.
Data Quality:
Look on the data source site (https://ladsweb.modaps.eosdis.nasa.gov) for quality information
File Format:
HDF

Related Documents

 LAADS DAAC - Search for Product Files
 LAADS DAAC - Data Archive
 File Specification
 LAADS DAAC DOI: 10.5067/MODIS/MOD04_L2.061

Process overview

This dataset was generated by instruments deployed on platforms as listed below.

Mobile platform operations

Mobile Platform Operation 1 Terra Satellite orbit details
Output Description

None
  • units: None
  • var_id: Deep_Blue_Spectral_Aerosol_Optical_Depth_Land
  • long_name: AOT at 0.412, 0.47, and 0.66 micron for land with all quality data (Quality flag=1,2,3)
  • units: None
  • var_id: Optical_Depth_Land_And_Ocean
  • long_name: AOT at 0.55 micron for both ocean (Average) (Quality flag=1,2,3) and land (corrected) (Quality flag=3)
  • units: None
  • var_id: Image_Optical_Depth_Land_And_Ocean
  • long_name: AOT at 0.55 micron for both ocean (Average) and land (corrected) with all quality data (Quality flag=0,1,2,3)
  • units: None
  • var_id: Deep_Blue_Aerosol_Optical_Depth_550_Land
  • long_name: AOT at 0.55 micron for land with all quality data (Quality flag=1,2,3)
  • units: None
  • var_id: Aerosol_Cldmask_Land_Ocean
  • long_name: Aerosol Cloud Mask 500 meter resolution 0= cloud 1= clear
  • units: None
  • var_id: Aerosol_Type_Land
  • long_name: Aerosol Type: 1 = Continental, 2 = Moderate Absorption Fine, 3 = Strong Absorption Fine,4 = Weak Absorption Fine, 5 = Dust Coarse
  • var_id: Average_Cloud_Pixel_Distance_Land_Ocean
  • long_name: Average Distance (number of pixels) to nearest pixel identified as cloudy from each clear pixel used for Aerosol Retrieval in 10 km retrieval box
  • units: Number of pixels
  • units: None
  • var_id: Deep_Blue_Spectral_TOA_Reflectance_Land
  • long_name: Average measured TOA reflectance after cloud screening at 0.412, 0.47, and 0.66 micron for land
  • var_id: Topographic_Altitude_Land
  • long_name: Averaged topographic altitude (in km) for Land
  • units: KM
  • units: None
  • var_id: Angstrom_Exponent_1_Ocean
  • long_name: Calculated Angstrom Exponent for 0.55 vs 0.86 micron for Average Solution
  • units: None
  • var_id: Angstrom_Exponent_2_Ocean
  • long_name: Calculated Angstrom Exponent for 0.86 vs 2.13 micron for Average Solution
  • units: None
  • var_id: Deep_Blue_Cloud_Fraction_Land
  • long_name: Cloud fraction from Deep Blue Aerosol cloud mask over land
  • units: None
  • var_id: Aerosol_Cloud_Fraction_Ocean
  • long_name: Cloud fraction from Land aerosol cloud mask from retrieved and overcast pixels not including cirrus mask
  • units: None
  • var_id: AOD_550_Dark_Target_Deep_Blue_Combined_Algorithm_Flag
  • long_name: Combined Dark Target, Deep Blue AOT at 0.55 micron Algorithm Flag (0=Dark Target, 1=Deep Blue, 2=Mixed)
  • units: None
  • var_id: AOD_550_Dark_Target_Deep_Blue_Combined
  • long_name: Combined Dark Target, Deep Blue AOT at 0.55 micron for land and ocean.
  • units: None
  • var_id: AOD_550_Dark_Target_Deep_Blue_Combined_QA_Flag
  • long_name: Combined Dark Target, Deep Blue Aerosol Confidence Flag (0= No Confidence (or fill), 1= Marginal, 2= Good, 3= Very Good)
  • units: None
  • var_id: Deep_Blue_Aerosol_Optical_Depth_550_Land_Best_Estimate
  • long_name: Deep Blue AOT at 0.55 micron for land with higher quality data (Quality flag=2,3)
  • units: None
  • var_id: Deep_Blue_Algorithm_Flag_Land
  • long_name: Deep Blue Aerosol Algorithm Flag (0=DeepBlue, 1=Vegetated, 2=Mixed)
  • units: None
  • var_id: Deep_Blue_Aerosol_Optical_Depth_550_Land_QA_Flag
  • long_name: Deep Blue Aerosol Confidence Flag (0= No Confidence (or fill), 1= Marginal, 2= Good, 3= Very Good)
  • units: None
  • var_id: Deep_Blue_Angstrom_Exponent_Land
  • long_name: Deep Blue Angstrom Exponent for land (between 412/470 nm for bright surfaces, 470/650 nm for vegetated surfaces) with all quality data (Quality flag=1,2,3)
  • units: None
  • var_id: Deep_Blue_Spectral_Single_Scattering_Albedo_Land
  • long_name: Deep Blue Single Scattering Albedo at 0.412, 0.47, and 0.66 micron for land with all quality data (Quality flag=1,2,3)
  • units: None
  • var_id: Deep_Blue_Spectral_Surface_Reflectance_Land
  • long_name: Deep Blue Surface Reflectance at 0.412, 0.47, and 0.66 micron for land with all quality data (Quality flag=1,2,3)
  • var_id: Cloud_Pixel_Distance_Land_Ocean
  • long_name: Distance (number of pixels) to nearest pixel identified as cloudy (500 m resolution)
  • units: Number of Pixels
  • units: micron
  • var_id: Effective_Radius_Ocean
  • long_name: Effective_Radius at 0.55 micron for 'best' (1) and 'average' (2) solutions
  • units: 1.0e-6g/cm^2
  • var_id: Mass_Concentration_Ocean
  • long_name: Estimated Column Mass (per area) using assumed mass extinction coefficients for 'best' (1) and 'average' (2) solutions
  • var_id: Mass_Concentration_Land
  • long_name: Estimated Column Mass(per area) using assumed mass extinction efficiency
  • units: 1.0e-6g/cm^2
  • units: None
  • var_id: Surface_Reflectance_Land
  • long_name: Estimated Surface Reflectance at 0.47,0.66 and 2.13micron
  • units: None
  • var_id: Deep_Blue_Aerosol_Optical_Depth_550_Land_Estimated_Uncertainty
  • long_name: Estimated uncertainty (one-sigma confidence envelope) of Deep Blue AOT at 0.55 micron for land for all quality data (Quality flag=1,2,3)
  • units: None
  • var_id: Optical_Depth_Ratio_Small_Ocean_0.55micron
  • long_name: Fraction of AOT (at 0.55 micron) contributed by fine mode for average solution
  • units: None
  • var_id: Optical_Depth_Ratio_Small_Land
  • long_name: Fraction of AOT contributed by fine dominated model
  • var_id: Latitude
  • long_name: Geodetic Latitude
  • units: Degrees_north
  • var_id: Longitude
  • long_name: Geodetic Longitude
  • units: Degrees_east
  • units: Degrees
  • var_id: Glint_Angle
  • long_name: Glint Angle
  • units: None
  • var_id: Asymmetry_Factor_Average_Ocean
  • long_name: Inferred Asymmetry_Factor for 'average' solution at 0.47, 0.55,0.66,0.86,1.24,1.63,2.13 um
  • units: None
  • var_id: Asymmetry_Factor_Best_Ocean
  • long_name: Inferred Asymmetry_Factor for 'best' solution at 0.47, 0.55,0.66,0.86,1.24,1.63,2.13 um
  • units: None
  • var_id: Backscattering_Ratio_Average_Ocean
  • long_name: Inferred Backscattering_Ratio for 'average' solution at 0.47, 0.55,0.66,0.86,1.24,1.63,2.13 um
  • units: None
  • var_id: Backscattering_Ratio_Best_Ocean
  • long_name: Inferred Backscattering_Ratio for 'best' solution at 0.47, 0.55,0.66,0.86,1.24,1.63,2.13 um
  • var_id: PSML003_Ocean
  • long_name: Inferred column number concentration (number per area) of particles larger than 0.03 micron for'best' (1) and 'average' (2) solutions
  • units: Particles/cm^2
  • units: None
  • var_id: Land_sea_Flag
  • long_name: Land_sea_Flag(based on MOD03 Landsea mask 0 = Ocean, 1 = Land and Ephemeral water 2 =Coastal)
  • units: None
  • var_id: Mean_Reflectance_Land
  • long_name: Mean reflectance of pixels used for land retrieval at 0.47,0.55,0.65,0.86,1.24,1.63,2.11 microns (plus extra bands for NPP: 0.412,0.443,0.745 Micron)
  • units: None
  • var_id: Mean_Reflectance_Ocean
  • long_name: Mean reflectance of pixels used for ocean retrieval at 0.47,0.55,0.65,0.86,1.24,1.63,2.11 microns(plus extra bands for NPP: 0.412,0.443,0.745 Micron)
  • units: None
  • var_id: Deep_Blue_Number_Pixels_Used_550_Land
  • long_name: Number of pixels used for AOT retrieval 0.55 micron for land
  • units: None
  • var_id: Number_Pixels_Used_Land
  • long_name: Number of pixels used for land retrieval at 0.47,0.55,0.65,0.86,1.24,1.63,2.11 Microns (plus extra bands for NPP: 0.412,0443,0.745 microns)
  • units: None
  • var_id: Number_Pixels_Used_Ocean
  • long_name: Number of pixels used for ocean retrieval at 0.47,0.55,0.65,0.86,1.24,1.63,2.11 Microns(plus extra bands for NPP: 0.412,0443,0.745 microns)
  • units: None
  • var_id: Land_Ocean_Quality_Flag
  • long_name: Quality Flag for Land and ocean Aerosol retreivals 0= bad 1 = Marginal 2= Good 3=Very Good)
  • units: None
  • var_id: Least_Squares_Error_Ocean
  • long_name: Residual of least squares fitting for inversion over land for best (1) and average (2) solutions
  • units: None
  • var_id: Optical_Depth_Small_Average_Ocean
  • long_name: Retreived optical thickness for fine mode (Average solution) for 0.47, 0.55,0.66,0.86,1.24,1.63,2.13 um
  • units: None
  • var_id: Optical_Depth_Small_Best_Ocean
  • long_name: Retreived optical thickness for fine mode (best solution) for 0.47, 0.55,0.66,0.86,1.24,1.63,2.13 um
  • units: None
  • var_id: Corrected_Optical_Depth_Land
  • long_name: Retrieved AOT at 0.47, 0.55,0.66 micron
  • units: None
  • var_id: Corrected_Optical_Depth_Land_wav2p1
  • long_name: Retrieved AOT at 2.13 micron
  • units: None
  • var_id: Optical_Depth_by_models_ocean
  • long_name: Retrieved AOT (at 0.55 micron) partioned by mode index (for Average solution)
  • units: None
  • var_id: Effective_Optical_Depth_Average_Ocean
  • long_name: Retrieved AOT for 'average' solution at 0.47, 0.55,0.66,0.86,1.24,1.63,2.13 um
  • units: None
  • var_id: Effective_Optical_Depth_0p55um_Ocean
  • long_name: Retrieved AOT for 'average' solution at 0.55um For easy L3 processing
  • units: None
  • var_id: Effective_Optical_Depth_Best_Ocean
  • long_name: Retrieved AOT for 'best' solution at 0.47, 0.55,0.66,0.86,1.24,1.63,2.13 um
  • units: None
  • var_id: Optical_Depth_Large_Average_Ocean
  • long_name: Retrieved AOT of large mode for 'average' solution at 0.47, 0.55,0.66,0.86,1.24,1.63,2.13 um
  • units: None
  • var_id: Optical_Depth_Large_Best_Ocean
  • long_name: Retrieved AOT of large mode for 'best' solution at 0.47, 0.55,0.66,0.86,1.24,1.63,2.13 um
  • units: None
  • var_id: Quality_Assurance_Ocean
  • long_name: Run time QA flags
  • units: None
  • var_id: Quality_Assurance_Land
  • long_name: Runtime QA flags
  • units: Degrees
  • var_id: Scattering_Angle
  • long_name: Scattering Angle
  • units: Degrees
  • var_id: Sensor_Azimuth
  • long_name: Sensor_Azimuth Angle, Cell to Sensor
  • units: Degrees
  • var_id: Sensor_Zenith
  • long_name: Sensor_Zenith Angle, Cell to Sensor
  • units: Degrees
  • var_id: Solar_Zenith
  • long_name: Solar Zenith Angle, Cell to Sun
  • units: Degrees
  • var_id: Solar_Azimuth
  • long_name: Solar_Azimuth Angle, Cell to Sun
  • units: None
  • var_id: Fitting_Error_Land
  • long_name: Spectral Fitting error for inversion over land
  • units: None
  • var_id: Deep_Blue_Aerosol_Optical_Depth_550_Land_STD
  • long_name: Standard deviation of Deep Blue AOT at 0.55 micron for land with all quality data (Quality flag=1,2,3)
  • units: None
  • var_id: STD_Reflectance_Land
  • long_name: Standard deviation of reflectance of pixels used for land retrieval at 0.47,0.55,0.65,0.86,1.24,1.63,2.11 microns (plus extra bands for NPP: 0.412,0.443,0.745 Micron)
  • units: None
  • var_id: STD_Reflectance_Ocean
  • long_name: Standard deviation of reflectance of pixels used for ocean retrieval at 0.47,0.55,0.65,0.86,1.24,1.63,2.11 microns(plus extra bands for NPP: 0.412,0.443,0.745 Micron)
  • units: Seconds
  • var_id: Scan_Start_Time
  • long_name: TAI Time at Start of Scan replicated across the swath
  • var_id: Wind_Speed_Ncep_Ocean
  • long_name: Wind Speed based on NCEP reanalysis for Ocean
  • units: Meters/sec
  • units: None
  • var_id: Solution_Index_Ocean_Large
  • long_name: index identifying coarse mode from Look Up Table for 'best' solution
  • units: None
  • var_id: Solution_Index_Ocean_Small
  • long_name: index identifying fine mode from Look Up Table for 'best' solution

Co-ordinate Variables

Coverage
Temporal Range
Start time:
2000-02-23T23:55:00
End time:
Ongoing
Geographic Extent

 
90.0000°
  
-180.0000°
  
180.0000°
 
-90.0000°
  
Related parties
Authors (1)
Publishers (1)
Principal Investigators (1)